"As a result, 18- to 29-year-olds are now roughly tied with seniors as the most likely of all age groups to hold this position on abortion -- although all four groups are fairly close in their views. This is a sharp change from the late 1970s, when seniors were substantially more likely than younger age groups to want abortion to be illegal," Gallup noted.

The polling agency also noted that generational differences in support for broadly legal abortion have diminished over the past decade.